Corviknight - Rookidee (Flying-type) evolves into Corvisquire (Flying-type) at level 18 and then into Corviknight (Flying/Steel-type) at level 38. This is a bit late for the first/second gyms, though. Rookidee can be found as a visible encounter on Routes 1 or 2.
Klink - Klink can be found as a hidden or overworld encounter in West Lake Axewell (the area right before you enter Motostoke) or North Lake Miloch, and has a 40% chance to show up during a Snowstorm as a hidden encounter, and 25% chance to show up during a Snowstorm as an overworld encounter. You can also find it as a hidden encounter on Route 3. It evolves into Klang at level 38, and then into Klingklang at level 49.
Bronzor - Bronzor can spawn as a hidden or overworld encounter at South Lake Miloch or at the Giant's Seat, with a 25% chance to spawn when the weather is Heavy Fog at South Lake Miloch, and with a chance to spawn as an overworld or hidden encounter during almost every weather at the Giant's Seat:
Snowing (5%) / Intense Sun, Overcast, Snowstorm (10%) / Raining, Sandstorm (25%) / Thunderstorm (28%) / Normal Weather (60%)
Excadrill - You can find Drilbur (Ground-type) that evolve into the Steel/Ground-type Excadrill at level 31 in Galar Mine No.1. They have a 10% chance to spawn as a visible encounter.
Galarian Meowth - You can find Galarian Meowth as a hidden encounter (35% chance) or as a visible encounter (23% chance) on Route 4, right before you reach Turffield. It evolves into Perrserker at level 28.
Ferroseed - Ferroseed also have a 1% chance to show up as a hidden encounter on Route 4. It evolves into Ferrothorn at level 40.
Bronzong can spawn in the Axew's Eye, but you can't access that until after the Circhester gym.
I believe those are all the Steel-types in the first Wild Area/Routes before you get to Turffield/first gym. If I missed anything, please comment.
Wild Area Encounters
Galar Mine No.1